A goal in each half from James Forrest 0 win over Motherwell in a top-three clash at Parkhead on Saturday.
Forrest fired Celtic in front after nine minutes when he latched onto a pass from Anthony Stokes to score from 12 yards.
Stokes played provider again shortly after the half-hour mark when his through ball allowed Joe Ledley to smash a shot past Motherwell goalkeeper Darren Randolph to double the advantage.
The Hoops went three goals up in the 67th minute when a 25-yard effort from Ki Sung-Yueng found the back of the net, while Forrest added a fourth goal six minutes later.
Celtic has opened the season with five wins from six games and sits one point back of Rangers, while Motherwell entered Saturday's contest having won three of its last four.
Rangers 1, Dundee United 0
Dundee, Scotland - Rangers remained on top of the SPL table on Saturday as Kyle Lafferty's second-half goal was enough to secure a 1-0 win over 10-man Dundee United.
United was reduced to 10 men on the half-hour mark when Johnny Russell was shown a straight red card for headbutting Kirk Broadfoot in an altercation.
This left United at a huge disadvantage, but it took until the hour mark for Lafferty to finally find the breakthrough as he headed the ball home from 10 yards after a nice ball from Greg Wylde.
Rangers has won five straight games since a draw on opening day, while United has lost three of its last five matches.
Inverness 1, Hearts 1
Inverness, Scotland - Hearts remained unbeaten in its last four games as a goal from Stephen Elliott nine minutes from time helped the Edinburgh side claim a 1-1 draw on Saturday.
Inverness went ahead early in the second half through Gregory Tade, but Elliott came to the rescue for Hearts when he volleyed home David Templeton's right-wing cross.
Kilmarnock 3, Dunfermline 2
Kilmarnock, Scotland - A pair of goals from Paul Heffernan propelled Kilmarnock to a 3-2 win over Dunfermline on Saturday, giving Killie its second win of the campaign.
An early goal from Dunfermline's Jason Thomson was canceled out by two from Heffernan before the break as he converted a penalty kick just after the half- hour mark and tallied another goal in the 44th minute.
Ryan Thomson scored early in the second half for Dunfermline to level the contest, but Zdenek Kroca put Kilmarnock back ahead for good in the 61st, dealing Dunfermline a second straight defeat.
St Mirren 0, St Johnstone 0
Paisley, Scotland - St Mirren and St Johnstone played to a 0-0 draw at St Mirren Park on Saturday, leaving both sides near the middle of the league table.
Chances were few and far between for both sides, but it was St Johnstone that had the best two as Nigel Hasselbaink missed the net after breaking through on goal, while Paul McGowan had a shot cleared off the goal line by St Mirren's Frazer Wright in the second half.